Ruptured pulmonary AV malformation presenting as spontaneous haemothorax in pregnancy.

We report a rare and potentially life-threatening case that emerged when a young postpartum woman presented with a ruptured pulmonary arteriovenous malformation (PAVM) resulting in spontaneous haemothorax. The patient, 3 days postpartum following a stillbirth at 36 weeks of gestation, arrived at the emergency department with worsening respiratory symptoms and right-sided chest pain for 5 days. The patient was haemodynamically stable with mild respiratory distress. The chest radiograph showed a moderate to massive right pleural effusion. An intercostal chest drain was inserted, and haemorrhagic effusion was drained. CT Pulmonary Angiogram revealed a PAVM in the medial basal segment of the right lower lobe with a right moderate haemothorax without active leak. Through prompt diagnosis and a multi-modal treatment approach combining minimally invasive interventions and surgical management, the patient initially underwent embolisation of the PAVM followed by video-assisted thoracoscopic surgery after 3 weeks for the removal of blood clots within the right pleural cavity.This case highlights the critical importance of considering PAVM rupture or vascular cause in the differential diagnosis of spontaneous haemothorax during pregnancy. Early identification and management of this condition can be life-saving to both the newborn and the mother.